This invention relates to a device for temporarily clamping sheets of paper of various sizes, such as memo sheets, which permits insertion and removal of one or a plurality of sheets of paper either collectively or individually in an easy and quick one-action operation by one hand.
An adhesive tape, a magnet, a drawing pin, a pin, a clip, and various other types of devices, have been used conventionally as a paper clip for temporarily fastening sheet(s) of paper such as memos.
Recently, devices for pressing and anchoring the sheets of paper by utilizing gravity dispersion vectors when a metallic ball or roller is placed on a slope have been proposed (e.g. Japanese Patent Unexamined Publication No. 53-87,818/1978 and Japanese Utility Model Publication No. 43-6,419/1968).
The inventor of present invention proposed the devices which can solve various problems with the prior art devices, as described above, and permit insertion and removal of the sheet(s) of paper by finger-tip manipulation.
A . . . Japanese Utility Model Publication No. 53-51,212 (Reg. No. 1,292,790) published on Dec. 7, 1978, entitled "One-Action Paper Clip". PA1 B . . . Japanese Patent Unexamined Publication No. 60-129,297/1985 published on July 10, 1985, entitled "One-Action Paper Clip".
Hereinafter, these prior art publications will be referred to as the "Prior Art A" and the "Prior Art B", respectively.
In one of the recent products, a specific adhesive is applied to the back of sheets of paper, such as memos, so that the sheets can be fitted and removed repeatedly to and from the fitting surface.
The conventional devices involve the following various problems.
The drawing pin and the pin involve the danger of hurting the human body; the adhesive tape involves a matter of consumption and contaminates the sheets or the fitting surface; the drawing pin and the pin damage the sheets and the fitting surface and can provide only one point of anchoring force, so that the fitting is unstable and unreliable; the appearance at the time of anchoring is clumsy in the case of the adhesive tape, the drawing pin and the pin; the magnet can be used under the condition that the fitting surface be made of a magnetic material; and all these conventional devices require, during the inserting and removing operation, two hands or two or more operations and cannot easily handle a plurality of sheets.
In case of the device employing a metal ball, the there is only one point of anchoring, so the sheets of paper become unstable and at the same time, the anchoring force is extremely low. Though the sheets of paper can be inserted gently from below when the sheets of paper are pulled out downwardly, they are caught between the metal ball and the fitting surface such as a substrate. In addition, the fitting surface must be a slope in order to obtain the function and effect. For these reasons, the device must inevitably have a relatively large thickness.
When a columnar member or roller is used in place of the metal ball, the anchoring force becomes higher and more stable than the metal ball because the force acts on a line, and insertion of the sheet can be made in the same way as in the metal ball. When the sheet is pulled out downwardly, however, the sheet cannot be pulled out because the catch force is far higher than that of the metal ball. Since the sheet cannot be pulled out in the horizontal direction, either due to the structure of the device, the operation of separating the columnar member from the sheet by fingers is first made and then the sheet is pulled out either in the horizontal direction or downwardly. The slope is essentially necessary to obtain such function and effect and the structure must inevitably have a relatively great thickness. Since the problems described above occur even when one sheet of paper is handled, a plurality of sheets cannot be inserted and removed reliably in either of these devices. Further, both of them utilize gravity dispersion vectors, and their fitting angle is not inherently free from the limitation.
The Prior Arts A and B proposed previously by the inventor of the present invention are directed to solve the various problems with the prior art devices and to make it possible to insert and remove a sheet(s) of paper in one action using two fingers of a hand.
With the device of the Prior Art A, one can insert and remove one sheet of paper in one action. Though Prior Art A solves the problems with other conventional devices to some extent, it is not yet free from the problems that made the development of a specific hair implanting machine necessary, and the hair tips of straight hair bundles open in the course of use and fail to keep good contact with a substrate, resulting reduced anchoring forces. Furthermore, when the sheet of paper is removed, the device permits the pull-out operation only in the horizontal direction due to its structural limitation.
The device of the Prior Art B can insert and remove not only just one sheet of paper but also a plurality of sheets in once action and is therefore extremely revolutionary. Although the device Prior Art B solves all the problems with prior art devices, the problem that sheet(s) of paper can be pulled out only along a line in the horizontal direction is left yet unsolved. Moreover, after sheet(s) of paper are accidentally pulled out downwardly, the rubber hairs that remain inverted completely inhibit the re-insertion of sheets in one action.
The principal constituent portions of the Prior Art B are shown in FIG. 9 of the accompanying drawings. As can be seen from this drawing, when the sheet 9 is pulled out downwardly, the rubber hairs 4 that have originally faced obliquely upwardly are pulled downward by the strong contact frictional force with the sheet 9 and thus are inverted as shown in the drawing. After the sheet 9 is pulled out, the hairs 4 cannot return to the original state on their own force because their movement is impeded by a fixed substrate 10, and thus they remain inverted.
To correct this inversion, it is necessary in the Prior Art B to insert once a thick sheet of paper such as a postcard by one hand or a thin sheet such as a memo by both hands from below to above in order to return them to their original state, and then to remove the sheet of the right or left in the horizontal direction.
The Prior Art B exhibits indeed excellent effects so long as it is used in accordance with its correct usage method, but one is apt to pull the sheet out downwardly or obliquely instead of pulling it out to the right or left in the horizontal direction, so that such troublesome correction work must be conducted whenever such mis-usage occurs.
The problem with the Prior Art B is as follows. When the sheet 9 is pulled out in a direction other than the horizontal direction such as the downward direction as in FIG. 9, the tips of the hairs 4, made of rubber, are moved in the interlocking arrangement by the strong frictional force with the sheet 9 and are then inverted downwardly so excessively that the hairs 4 cannot return automatically to their original state as their motion is impeded by the substrate 10 which is fixed and cannot move at all.
Next, the memos or the like which have been put on the market recently and are coated with an adhesive are advantageous because they do not require any devices. However, they involve the following various problems. First of all, it is not easy to write on the memos due to the thickness of the bundle of sheets. If they are peeled off one by one, they become very sticky. As a matter of fact, coating of the adhesive is the essential condition and for this reason, various sizes of sheets to cope with various intended applications must be prepared in advance. When a plurality of sheets are bonded onto a wall surface or the like, it becomes difficult to take out a lower one of them. The price of each sheet is very expensive and the sum in the course of use becomes very high. Moreover, sheets of regular uncoated paper cannot be clipped at all.